The "Library" section of _oasis allows to specify (via the "Modules:" field) the modules to be included into the library. It would be interesting to extend the syntax of "Modules:" allowing to also specify a path, in case the source file is located in a subdir of "Path:"

Library foo
Path: .
Modules: Mod1, subdir/Mod2

The "Modules:" field would be useful even in "Executable" sections, for the same reason.